21434400500 has 48 divisors (see below), whose sum is σ = 47250350784. Its totient is φ = 8493610400.

The previous prime is 21434400469. The next prime is 21434400523. The reversal of 21434400500 is 500443412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 146822 + ... + 253821.

It is an arithmetic number, because the mean of its divisors is an integer number (984382308).

Almost surely, 2^21434400500 is an apocalyptic number.

21434400500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21434400500 is an abundant number, since it is smaller than the sum of its proper divisors (25815950284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21434400500 is a wasteful number, since it uses less digits than its factorization.

21434400500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400769 (or 400757 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

Adding to 21434400500 its reverse (500443412), we get a palindrome (21934843912).

The spelling of 21434400500 in words is "twenty-one billion, four hundred thirty-four million, four hundred thousand, five hundred".